Five Things You Don't Know About Caroline Kennedy

She grew up in one of America’s most famous families, but Caroline Kennedy has always shunned the public life – until now.

This week, the only surviving child of John F. and Jackie Kennedy begins a quest to win the U.S. Senate to be vacated when Hillary Clinton joins Barack Obama’s cabinet. (Clinton’s replacement will be appointed by New York’s governor.)

Kennedy, 51, is married to New York designer Edwin Schlossberg. They have three children, Rose, 20, Tatiana, 18, and Jack, 15. She is a lawyer, author and fundraiser. But did you know she learned to talk while her dad was running for president, first uttering the words “plane,” “goodbye” and “New Hampshire”?

More facts about Kennedy:

• She has a tattooWhile on a trip to Hong Kong in the ’80s, Caroline and cousin Kara Kennedy were challenged by male family members – John F. Kennedy Jr. and Teddy Kennedy Jr. – to get inked, the New York Post reports. Kennedy flashed the resulting butterfly tattoo, on the inside of her right forearm, at this year’s Democratic National Convention in Denver.

• She inspired the song "Sweet Caroline"Neil Diamond revealed last year that he wrote his 1969 hit “Sweet Caroline” in honor of the slain president’s daughter. “I’ve never discussed it with anybody before – intentionally,” Diamond told the Associated Press. “I thought maybe I would tell it to Caroline when I met her someday.” He did, when he performed the song for her live via satellite at Kennedy’s 50th birthday party.

• She volunteered as a school crossing guardAccording to the New York Times, Kennedy, who persuaded wealthy New Yorkers to donate millions to the city’s schools, was not too proud to don a reflective vest and stand in traffic as a school crossing guard at her children’s own (private) school.

• She gets stage frightEven with her pedigree, Caroline still has moments of self-doubt. In 1999, the year after her brother John’s death in a plane crash, social worker Rosa Pardo received an award from the Robin Hood Foundation, a favorite Kennedy charity. Caroline was at the ceremony on behalf of her brother and was sitting at the same table as Pardo, who told PEOPLE that Kennedy was as nervous as she was about standing up before the large crowd. “She’s a normal everyday person,” says Pardo.

• Her likeness is a hot collectibleDozens of Caroline Kennedy items have shown up on eBay, including her books (In Our Defense and Right to Privacy), photos and dolls. The rarest? The Caroline Kennedy First Lady Dress-Up Book – a 1963 paper doll set featuring then 5-year-old Caroline in historic First Lady attire. Because of JFK’s assassination, the book was shelved just before its planned release. Only a few copies remain and are worth up to $900.